Conventionally, a paper feeding device for supplying sheets of paper is provided in an apparatus such as a copying machine. As shown in FIG. 16 through FIG. 18, in some paper feeding devices, a rotatable paper tray unit 72 having a rotatable paper tray 71 installed therein is supported to a feeding device main body 74 by a sliding mechanism 73 and thereby adapted to be drawn from the feeding device main body 74 so as to store or exchange sheets of paper. A state of attachment of the rotatable paper unit tray 72 to the feeding device main body 74 is detected by a sensor (not shown).
In order to permit either longitudinal or lateral feeding of sheets of paper stored therein, the rotatable paper tray 71 is adapted to reversibly rotate to either a lateral feeding position shown by a solid line in FIGS. 16 and 17 as well as shown in FIG. 18 or a longitudinal feeding position shifted from the above position by an angle of 90.degree. , which is shown by an alternate long and two short dashes line in FIG. 16 and FIG. 17.
The rotation of the rotatable paper tray 71 is performed by a mechanism wherein a movable member 75 coupled to one corner of the rotatable paper tray 71 is shifted by the rotation of a rotative threaded shaft 76 having a thread on its surface. Further, the longitudinal or lateral feeding position of the rotatable paper tray 71 is detected by a mechanism that a projecting member 75a attached to the movable member 75 is detected by a longitudinal feeding position sensor 78 or a lateral feeding position sensor 79 installed in a tray housing 77.
The sensors 78 and 79 are connected to a control device, not shown, installed in the feeding device main body 74 through a harness 80 and a connector 81. While the longitudinal or lateral feeding position of the rotatable paper tray 71 is detected by the sensor 78 or 79, various operations such as the next rotation operation of the rotatable paper tray 71 and a feeding operation from the rotatable paper tray 71 are executed by instructions from the control device (not shown).
However, in the above conventional arrangement, since the longitudinal and lateral feeding position sensors 78 and 79 are installed in the rotatable paper tray unit 72 and connected to the feeding device main body 74 by the harness 80, a wiring process of the harness 80 should be carried out by taking into account attaching and removing operations of the rotatable paper tray unit 72 to and from the feeding device main body 74. This process causes complicated work.
Moreover, the conventional arrangement requires the connector 81 for connecting the harness 80 to, for example, the feeding device main body 74 and a number of sensors such as those for detecting a state of the rotatable paper tray unit 72 whether it is attached to or removed from the feeding device main body 74 and those longitudinal and lateral feeding position sensors 78 and 79. This causes such a drawback that necessary parts are increased in number.
As illustrated in FIG. 19 and FIG. 20, in another arrangement, the longitudinal or lateral feeding position of the rotatable paper tray 71 is detected by a longitudinal-lateral position detector for rotatable paper tray, which is provided with a light interrupting plate 75a' normally coupled to the rotatable paper tray 71 so as to be shifted along the rotative threaded shaft 76 in accordance with the rotation of the rotatable paper tray 71, and further provided with optical longitudinal and lateral feeding position sensors 79' and 78' installed in the tray housing 77 of the rotatable paper tray unit 72 for detecting the light interrupting plate 75a'.
The sensors 78' and 79' are connected to a control device, not shown, installed in the feeding device main body 74 through a harness 80 and a connector 81. While the longitudinal or lateral feeding position of the rotatable paper tray 71 is detected by the longitudinallateral position detector for rotatable paper tray, various operations such as the next rotation operation of the rotatable paper tray 71, a raising operation of a paper carrying plate, not shown, in the rotatable paper tray 71 and feeding operation from the rotatable paper tray 71 are executed by instructions of the control device.
However, in the above conventional arrangement, since the longitudinal and lateral feeding position sensors 78' and 79' are installed in the rotatable paper tray unit 72 and connected to the feeding device main body 74 by the harness 80, a wiring process of the harness 80 should be carried out by taking into account attaching and removing operations of the rotatable paper tray unit 72 to and from the feeding device main body 74. This process causes complicated work. Further, the arrangement requires the connector 81 for connecting the harness 80 to, for example, the feeding device main body 74 and other devices, thereby causing such a drawback that required parts are increased in number.